1. Field of the Invention
The present invention relates to a heat sink and, more particularly, to a heat sink for the drill bit of a drill press.
2. Description of the Related Art
A conventional heat sink for a drill press in accordance with the prior art shown in FIGS. 6-8 comprises a main body 50, a guide tube 60 mounted on the main body 50, and a sponge 70 mounted in the main body 50. The main body 50 has an inner portion provided with a receiving chamber 52 which has a top provided with a protruding limit tube 53. The limit tube 53 of the main body 50 has a size smaller than that of the receiving chamber 52 of the main body 50. The main body 50 is provided with two suckers 51 to attach the main body 50 to a working surface (not shown). The main body 50 has a mediate portion provided with a shoulder 54 defined between the receiving chamber 52 and the limit tube 53. The guide tube 60 is mounted on the receiving chamber 52 of the main body 50 and protrudes outwardly from the limit tube 53 of the main body 50. The guide tube 60 has an inner portion provided with a guide hole 61 and has a lower end provided with an enlarged stop flange 62 received in the receiving chamber 52 of the main body 50 and abutting the shoulder 54 of the main body 50. The sponge 70 abuts the bottom of the stop flange 62 of the guide tube 60 and received in the receiving chamber 52 of the main body 50. The sponge 70 contains a cooling agent (not shown) therein. The sponge 70 has an inner portion provided with a through hole 71.
In operation, the limit tube 53 of the main body 50 aligns with a predetermined position of a working surface (not shown). Then, the main body 50 is attached to the working surface by the suckers 51. Then, the drill bit of a drill press in turn passes through the guide hole 61 of the guide tube 60 and the through hole 71 of the sponge 70 and is inserted into the working surface to drill a hole in the working surface. At this time, the cooling agent contained in the sponge 70 is released to a periphery of the drill bit to provide a heatsink effect to the drill bit so as to decrease the high temperature produced on the drill bit during the drilling process.
However, the guide hole 61 of the guide tube 60 is only available for the drill bit of a single size and cannot be used to fit drill bits of different sizes, thereby decreasing the versatility of the heat sink. In addition, a user has to prepare multiple heat sinks for drill bits of different sizes, thereby increasing the cost of fabrication.